Carrier sense and channel reservation mechanisms are used in a wireless local area network (WLAN) system. After a period of time on a channel is reserved by a station, another station is not allowed to perform data sending during the period of time. In the prior art, when an access point (AP) successfully reserves a time-frequency resource, only the access point can use the time-frequency resource, and a non-associated neighboring station of the AP does not perform data sending on the time-frequency resource. Therefore, there is a problem of low efficiency in transmitting data in the prior art.